1. Field of the Invention
The present invention generally relates to transmission units having a continuously variable transmission module and a planetary transmission module. More particularly, the present invention relates to such transmission units in which the fluid flow is integrated, the modules are separable and the control of the continuously variable transmission module can be performed without electronics.
2. Description of the Related Art
Transmissions are known that combine continuously variable transmission components with planetary components. Most of these transmissions require separate assemblies that are not useful with other types of non-integrated transmissions. Furthermore, such constructions are limited in the ability to adjust the structures to accommodate differing needs between differing vehicles.
Moreover, most of the continuously variable transmissions in use require complicated electronic control strategies. Such strategies gather information from engine and driveline sensors, including the driver actuated throttle position. The gathered information is used to control the ratio changing and chain clamping forces by selective manipulation of the hydraulic system pressures. These systems are complex and feature many components that increase the cost of manufacture.